I've travelled all over the world bud, and North America is the only place with such foolish security measures. I really don't mind the searches, pat down or anything else but asking for receipts is a truly North American thing. Just as useless as Walmart/Costco receipt checkers. What would he do if I didn't have anything? Confiscate my newly purchased shoes that I held in the vendors bag?
My feedback was only for the vendors; ensure your customer knows he needs to produce a receipt at the door. Thank the Lord the police officer had more sense.